Check External Power Sources

One step in the repair process of an electrical motor is to rule out other cause of power failure. Check the electric outlet that powers the electric motor has power by plugging in a different object that definitely works, such as a radio or a lamp. If the outlet does not have power, then check to make sure the circuit breaker is on and reset it to the on position if it is not. Plug the radio or lamp back into the outlet and if it works, check the item with the electrical motor and plug it in. If it does not power up, then the next phase of the repair is in order.

Power Cord and Other Wires

There are two wires used to connect the motor to the power cord. Remove the wires and use the jumper wires to connect them together. If jumper wires are not available, perform the same test by splicing the wires together. The voltmeter has two leads that now need to connect to each individual wall plug connector. Adjust the voltmeter setting to the RX1 then scale the meter while twisting the power cord..If the cord is not faulty, the screen displays a "0" Ohm rating. If the screen displays a number higher than that, this means that the problem lays within the power cord and replacing it tends to solve this problem.

Motor Power Switch

The next step in the process is to check the motor power switch to make sure that it is functioning properly. Repeat the same process to test the switch using the voltmeter and the two wires that connect the motor and switch together. Keeping the voltmeter set to the same scale as the power cord test, turn the switch of the motor on and then back off again. If the motor power switch functions properly, the voltmeter screen displays a "0" when switch is off and a high number reading when the switch is off. If the reading remains unchanged, the problem lies in the switch and it needs replacing.

Commutator

The commutator is the piece of the electric motor that rotates within that change the electrical current that runs between the circuit and the rotor. Inside the housing of the motor is a field coil and at least two small brushes. The brushes are metallic and make direct contact with the commutator. In order to access the commutator, loosen and remove the screws that hold together the motor housing. Inspect the commutator for corrosion, dirt, or other debris which may be keeping the commutator from receiving a good electrical connection. Remove any foreign material by sanding the surface of the component lightly with the fine grit sandpaper while rotating the commutator.

As with the previous voltmeter tests, connect the unit to the commutator space bars and make sure the meter is still on a RX1 scale setting. A high Ohm reading is a good thing. If the voltmeter displays a "0"reading, the commutator needs replacing. Perform the test in the same manner again, only this time test the field coil. A high Ohm reading in this case means the field coil is defective. The brushes should be making direct contact with the commutator and if they are not firmly in place, check the brush springs and adjust them if the pressure applied to the commutator is not firm and even. Replace and brush or springs that are defective.